This invention relates to energy conservation and, more particularly, this invention relates to a system for conditioning the air in a building in an efficient and economical manner.
Conventional devices for heating and cooling the interior of buildings rely heavily on the use of energy derived from fossil fuel. Heating systems rely, either directly or indirectly on the combustion of such fossil fuels as oil and gas. Similarly, cooling systems indirectly rely, almost exclusively, on the combustion of fossil fuels. Those heating or cooling units which do not, themselves, burn oil or gas, are powered by electricity which, in turn, is generated by the combustion of oil, gas, or coal. With the ever-diminishing supplies of fossil fuels on this planet Earth, the cost of producing the energy has risen dramatically. At the same time, the finite resources of fossil fuels are rapidly becoming depleted.
Yet, there is an abundance of energy derived from the sun which is being totally wasted. Present technology for harnessing solar energy is expensive and inefficient.
Various devices for utilizing solar energy to heat a fluid which is to be used at a location remote from the solar energy collector are known in the art. As representative of the prior art devices are those disclosed by Rountree in U.S. Pat. No. 1,003,514, dated Sept. 19, 1911; by Nichols in U.S. Pat. No. 1,047,554, dated Dec. 17, 1912; and by Chevalier in U.S. Pat. No. 3,968,652, dated Jul. 13, 1976. There are many and varied devices for capturing and utilizing solar energy, as represented by the devices disclosed in the aforementioned U.S. patents. There are, additionally, means for increasing the efficiency of these solar energy devices which are, inherently, inefficient, being limited by the physical surface area provided for collecting the sun's rays. Quite often, these efficiency-increasing means are in the form of reflectors for assisting in collecting and directing the rays of the sun to a particular location. These means are exemplified by Daymon in U.S. Pat. Nos. 3,028,856, dated Apr. 10, 1962; and by Clevett et al. in 4,446,854, dated May 8, 1984.
Moreover, since conditioning the air in a building is essentially a heat exchange process, it follows that it can be made more efficient and economical by taking advantage of other naturally occurring phenomenona. For instance, it is known that the temperature of the ground, below a certain depth depending on the latitude of a particular location, is essentially constant at about 50.degree. F. Thus, it should be possible to take advantage of the temperature gradient between the ambient air and the ground at that depth. An early attempt at taking advantage of the cool temperature below ground was made by Frick in U.S. Pat. No. 165,486, dated July 13, 1875. Frick relied on the natural generation of convection currents to carry cool air from the ground, through duct work, into a building. In U.S. Pat. No. 2,217,190, granted to Urquhart on Oct. 8, 1940, a complicated system of conduits is disclosed for transferring air from an underground vault having porous walls to a building. In U.S. Pat. No. 2,793,509, granted to Keen on May 28, 1957, there is disclosed another complex system of buried conduits, each having an inlet end opened above ground and an outlet end connected to a manifold which, in turn, is connected to the inlet end of a fan thereby causing outside air to be drawn into the conduits, passing underground, and then passing into a building. U.S. Pat. Nos. 4,279,291 and 4,449,572, both in the name of Lambert, disclose a system to be used in conjunction with a heat pump. The Lambert system essentially comprises a buried U-shaped conduit through which air is passed before going to the heat pump. A complicated cross-over conduit arrangement is provided to cause recirculation of a portion of the air. Another complicated buried heat exchange system is disclosed in U.S. Pat. No. 4,388,966, granted to Spiegel on June 21, 1983.
To the best of the present Applicant's knowledge, however, there has not been a system for conditioning air in a building which utilizes a combination of elements taking advantage of both solar energy and other natural energy sources, and which is simple and economical.